Machine for packing sand in a mold box



Aug. 23, 1955 R. w. TACCONE 2,715,758

MACHINE FOR PACKING SAND IN A MOLD BOX Filed April 3, 1952 2 Sheets-Sheet l INVENTOR. Russell W. Taccone HIS ATTORNEYS Aug. 23, 1955 Filed April 3, 1952 R. w. TACCONE 2,715,758

MACHINE FOR PACKING SAND IN A MOLD BOX 2 Sheets-Sheet 2 HIS TTOR/VE Y5 United States Patent MACI-HNE FOR PACKING SAND IN A NIOLD BOX Russell W. Taccone, North East, Pa., assignor to Taccoue Pneumatic Foundry Equipment Corporation, North East, Pa., a corp oration of Pennsylvania Application April 3, 1952, Serial No. 230,223

7 Claims. (Cl. 22-42) ing application Serial No. 184,587, filed September 13. L-.

1950, now abandoned.

In the accompanying drawings which illustrate a preferred embodiment of my invention- Figure 1 is a section taken on line I--I of Figure 4, showing the flexible diaphragm withdrawn from the mold box and received in the head;

Figure 2 is a view similar to Figure 1, but showing the flexible diaphragm dropped into the mold box and ready to be expanded so as to pack sand in the mold box;

Figure 3 is a view similar to Figure 1, but showing the flexible diaphragm expanded so as to pack sand in the mold box;

Figure 4 is a front elevation of my molding machine; and

Figure 5 is a section taken on the line VV of Figure 2.

In prior known molding machines wherein a flexible diaphragm or obtruder has been employed for packing sand in a mold box, the flexible diaphragm has been secured to a head, and after a pattern has been placed in the mold box and the mold box has been filled with sand or other molding agent, the mold box has been brought under the head and then either the head has been lowered or the mold box and its support have been raised so as to close the gap between the upper edge of the mold box and the lower edge of the head. The head has then been clamped to the mold box or to the support on which the mold box is mounted, and the flexible diaphragm has been expanded in order to pack sand in the mold box. Where a flexible diaphragm has been employed, it has always been considered necessary to eliminate any gap between a the top edge of the mold box and the lower edge of the head since otherwise it has been thought that upon inflating the diaphragm, the diaphragm would bulge out through the gap and would burst. in order to close the gap between the upper edge of the mold box and the lower edge of the head, it has been necessary to the head and the support on which the mold box is mounted movable vertically relative to each other. This has involved considerable expense, particularly in those cases where the mold is a large one, as for example a mold and head having dimensions of the order of, say, ft. long and 4 ft. wide. In addition, where there is relative vertical movement between the head and the support for the mold box, time is consumed in closing the gap and clamping the head and mold box together prior to the inflation oi the flexible diaphragm.

These disadvantages of prior known molding machines are overcome in accordance with my invention. lily molding machine comprises a support for a mold box and a head located above the support a suflicient distance so that when a mold box is placed on the support, there is a gap between the top edge or" the mold box and the botice tom edge of the head. The head and the mold box support are immovable vertically relative to each other. The head carries a flexible diaphragm which, in the operation of the machine, can be drawn upwardly into the head to make room for sliding a mold box onto the support and which can be expanded to compress sand in the mold box.

in the use of my machine, a pattern is placed in the mold box the mold box is filled with sand while the mold box is not underneath the head. The mold box filled with sand and containing the pattern is then moved onto the mold box support which is located underneath the head, with a gap between the top edge of the mold box and the lower edge of the head. The flexible diaphragm is then inflated while the gap is still present, in order to compact the sand in the mold box. I make the gap so small that when the flexible diaphragm is inflated, it is prevented from extending through the gap. The gap may be any distance less than twice the thickness of the diaphragm, and it will still prevent bulging of the diaphragm through the gap. As an example, if the thickness of the flexible diaphragm is A1", I have found that the gap can be any dimension less than /2". After the sand has been compacted in the mold box, the flexible diaphragm is drawn upwardly into the head and the mold box is removed from the support. In carrying out my invention, 1 eliminate the operation of closing the gap between the bottom edge of the head and the top edge of the mold box, and I also eliminate the operations of locking and unlocking the head to the mold box, thereby speeding up the operation considerably.

Referring more particularly to the accompanying drawings, my molding machine comprises a base 2 and two spaced apart C-shaped frame members 3 integral with the base. Each of the frame members 3 has a lower portion 4, an upper portion 5, and a vertical portion 6. A mold support or platform '7 extends between the frame members 3. A head 8 also extends between the frame members and is located above and spaced from the mold support. The head 3 is or" corrugated construction providing channels 9 having ports 19 therein. The head 8 is integrally connected to the mold support 7 by a vertical wall 11 extending between the frame members 3. A pattern plate 12 and pattern 13 are shown on the mold support 7. A mold box 14 is placed on the pattern plate, the mold box being provided with a flange 15 having openings 16 for receiving pins 17 extending upwardly from the pattern plate.

A flexible diaphragm or obtmder 18 made or" flexible rubber or any other flexible material is secured at its marginal portions 18:: to the lower edge of the head 8 by means of a clamping ring 19 and screw bolts 20 received in holes in the clamping ring and holes 21 provided in the head. The flexible diaphragm, in its unexpanded condition, has a surface area substantially greater than the cross-sectional area of the head 8 so that it hangs loosely from the head. Reinforcing members 24- which are flexible but stiffer than the diaphragm 18 are secured between the marginal portions 18a of the diaphragm and the clamping ring 1? to prevent the diaphragm from being forced outwardly between the top edge 14a of the mold box 14 and the clamping ring 19. These reinforcing members 24 also protect the marginal portions of the diaphragm from damage. They are wide enough to span the opening or gap between the top edge of the mold box and the clamping ring 19.

The ports 19 in the head 8 are connected by a T 25, a cross 26, and an elbow 27 to a pipe 28 leading to an exhaust fan 29 driven by a motor 39 and having an exhaust outlet 2%. A valve 31 is interposed in the pipe 28 between the fan 29 and the openings 10 in the head 8, this valve 31 being opened and closed by auxiliary air pressure supplied to the valve 31 through a pipe 32. Flow of air through the pipe 32 is controlled by an auxiliary valve 33; Y

a Air or other'fluid under pressure for expanding the dia phragm 18 is supplied through a pipe 34, elbow 35, valve 7 36, pipe 37, cross 26,'pipe 28, T 25, elbow 27, and openmgs 1 to the head. 'The valve 36 is opened and closed }by means of auxiliary air flowing through pipe 39 and controlled by auxiliary valve 40. V

In the operation of my molding machine, the mold box 14 containing the pattern 13 is filled'with sand or a suitable molding agent while'the mold box is on a conveyor or other support which is not located underneath the head, 8: The exhaust fan 29 operates continuously, and acts to maintain the flexible diaphragm 18 in the channels 9 in the head 8 when the valve 31 is open, as shown in Figure l.

' f After the mold box is filled with sand, it is slid onto the support 7 underneath the head 8 while the flexible diaphragm 18 is held in the channels in the head by the ex- :haust 'fan 29; The valve 31" is then closed by operating valve 33, whereupon the diaphragm 18 falls onto/the sand Sin the mold box,as shown in Figure 2. The area of the flexible. diaphragm is considerably larger than the crosssectional area of the mold box 14 so that the flexible diaphragm liesfon the sand in closed folds 44. The reason for forming these folds 44 is that it has been found that where the diaphragm 18 is fastened at its margin and there is no provision for expansion thereof except the elasticity of the material of which the diaphragm is made," the marginal edges of the diaphragm are quickly torn away from the fastenings and the molding operation can only be performed a relatively few times. By providing excess 7 area of the diaphragm, this tearing away of the diaphragm from the fastenings, is eliminated orinhibited, all the stretching and strains that occur throughout the entire area, of ,the diaphragm while under pressure are eliminated,

and the mold life of the diaphragm is greatly increased.

Air under pressure is then admitted to the space between the head 8 and the diaphragm-18 in order to' expand the diaphragm, and cause it to pack the sand in the 'mold. In order to expand the diaphragm, valve 40 is operated to open valve 36 thereby allowing air under a pressure entering pipe 34 to flow through pipe 37 and cross 26 into pipe 28, and from there to flow through fittings 25, 26 and 27 and ports into the space between the head and the flexible diaphragm 18. The diaphragmis shown in its expanded position in Figure 3, from which it will be noted that even in its fully expanded position in 4 and the mold can be slid off from the support 7 'onto a conveyor, all without moving the support 7 or head 8 relative to each other, or clamping the head in any manner tothe mold box. The elimination of these steps greatly speeds up the molding operation.

The provision of the channels9 in the head 8 serves several important functions. The channels provide suitable linear area for withdrawing the diaphragm into the head. They decrease the volume of air necessary to expand the diaphragm into contact with the sand, and therefore substantially speed up the squeezing cycle. Furthermore, they assist in forming the folds 44 when the dia phragm falls onto the 'top of the sand'in the mold box. 7 It should be understood that when I use the word sand, I mean any molding agent which is suitable for making a mold. My machine may be used for making cores by utilizing the flexible diaphragm to force the sand into a core box, and thereafter cutting off the cores. 7

The invention is not limited to the preferred embodiment, but may be otherwise embodied or practiced within the scope of the following claims. h

exhaust fan' 29 withdraws the flexible diaphragm into the i channels 9 of the head 8 as shown in Figure 1, and then the mold box .14, pattern 13 and pattern plate 12 are removed from the support 7. The cycle may then be repeated. V a

The use of the reinforcing member 24 can be omitted where the gap between the top edge 14a of the mold'boxj 14 and the lower edge of the clamping ring 19 is su fficiently small so as to prevent the diaphragm from bulging out through the gap when it is expanded. As previously explained, this bulging will be prevented by making'th'e gap less than twice 'thethickness of the diaphragm. My molding machine is readily adapted to conveyor line I operation because the spaced-apart relatively immovable :head 8 and mold support 7 allow mold boxes 14 to be slid from a conveyor onto the support 7 into a position under-- neathlthe head in order to allow compacting of the'sand'i upon expansion of the'fiexible diaphragm, after which the flexible diaphragm can. be withdrawn into the head I claim: V l. A molding machine comprising a support for a mold box, a head supported above said support in fixed spaced relation thereto, said head having a wall forming an open cavity, a flexible relatively thick obtruder secured to said head forming a closed chamber in said head cavity andf movable thereinto prior to molding, a mold boxadapt'ed 1 to be moved laterally on said support to position said.

mold box under said head, said head and said support being spaced apart to receive a mold box having a height to leave a clearance gap between said mold box and said head, the clearance gap being less than twice the'thickness of said obtruder whereby said mold box is freely slidable between said'head and said support, said mold box being adapted to receive molding material, the'area of 7 said obtruder being considerably greater than the cross sectional area of said mold box, and means to supply fluid under pressure to said chamber to move said obtruder into engagement with said molding'materialto compress said molding material into molded condition. 7

2. A molding machine comprising a support for a mold box, a head supported above said support in fixed spaced relation thereto, said head having a wall forming an open cavity, a flexible relatively thick'obtruder secured to saidhead forming a closed chamber in saidrhead cavity and movable thereinto prior to molding, a mold box'adapted to be moved laterally on said support to' position said mold box under said head saidhead and said support being spaced apart to receive said mold box having suf- 'ficient height to leave a clearance gap between said mold box and said head, the clearance gap being'less than twice the thickness of said obtruder whereby-said mold. box is freely slidable between said head and said support; said mold box being adaptedto receive molding material; 7 the area of said obtruder being considerably greater than the cross sectional area'of said mold box, means to supply fluid under pressure to said chamber to move said obtruder into engagement with said molding material to compress said molding material 7 being secured to said head by means of a clamping ring, and vacuum means to withdraw said obtruder into said head.

3. A molding machine comprising a support for a mold box, a head supported above said support in fixed spaced relation thereto, said head having a Wall forming an open cavity, a flexible relatively thick obtruder secured to said head forming a closed chamber in said head cavity and movable thereinto prior to molding, a mold box adapted to be moved laterally on said support toposition -said mold box under said head, said head andsaid support being spaced apart to receive said mold box having sufficient height to leave a clearance gap between said mold into molded condition, said obtruder freely slidable between said head and said support, said mold box being adapted to receive molding material, the area of said obtruder being considerably greater than the cross sectional area of said mold box, means to supply fluid under pressure to said chamber to move said obtruder into engagement with said molding material to compress said molding material into molded condition, said obtruder being secured to said head by means of a clamping ring, and vacuum means to withdraw said obtruder into said head, said head being provided with downwardly opening channels extending across its inside surface for receiving said flexible obtruder when the obtruder is withdrawn in said head.

4. A molding machine comprising a support for a mold box, a head supported in fixed spaced relation thereto, a flexible obtruder secured to said head, means to support said obtruder in spaced relation to said mold box prior to molding, a mold box adapted to be moved to a position between said head and a base to position said mold box between said base and said head, said space between said base and said head being adapted to receive said mold box with a clearance gap therebetween whereby said mold box is freely movable between said head and said support, the clearance gap being less than twice the thickness of said obtruder, said mold box being adapted to receive molding material, and means to apply fluid under pressure to the side of said obtruder remote from said molding material whereby said obtruder is forced into engagement with said molding material and said obtruder is forced to extend across said gap, said molding material being packed in said mold box.

5. A molding machine comprising a support for a mold box, a head supported in fixed spaced relation thereto, a flexible obtruder secured to said head, means to support said obtruder in spaced relation to said mold box prior to molding, a mold box adapted to be moved to a position between said head and said support to position said mold box between said support and said head, said space between said support and said head being adapted to receive said mold box with a clearance gap between said head and said mold box, means to seal said gap between said head and said mold box, said mold box being adapted to receive molding material, and means to apply fluid under pressure to the side of said obtruder remote from said molding material whereby said obtruder is forced into engagement with said molding material and forced to extend across said gap and said molding material is packed in said mold box.

6. The molding machine recited in claim 5 wherein said means for sealing said gap comprises a reinforcing member attached to said obtruder around the portion thereof adjacent to said gap and adapted to overlie said gap when said obtruder is in the molding position.

7. The molding machine recited in claim 5 wherein said obtruder is attached to said head around its marginal edges to provide a chamber for fluid under pressure between said head and said obtruder, said means comprising a reinforcing member attached to said obtruder around its marginal edges and adapted to be disposed across said References Cited in the file of this patent UNITED STATES PATENTS 302,349 Moore July 22, 1884 318,784 Moore May 26, 1885 408,386 Moore Aug. 6, 1889 2,336,428 Watson Dec. 7, 1943 2,654,901 Morrison Oct. 13, 1953 FOREIGN PATENTS 460,014 France Sept. 23, 1913 

